TCM Magneto; 10-682560-13; Teeth Missing--Distribution Gear; ATA 7414

TCM Magneto; 10-682560-13; Teeth Missing--Distribution Gear; ATA 7414

A Piper PA-32R arrived at a mechanic’s hangar with a rough running engine. Diagnostics determined one side of the dual magneto was dead. Upon removal and disassembly, this magneto’s defect became clear: multiple teeth were missing from the timing gear. The owner described this particular magneto as “...low time,” but no specific hours were provided. Aircraft total time was given as 2,289.8 hours. (Gear part number not provided. See an example in the next Alert item’s attached photograph.)